How pure will this language be?

This language needs mutation, it’s supposed to be fast and mutation is also just very useful.

Hopefully with rust ownership reasoning about this mutation will be a lot easier.

Regular functions will be able to have side effects.

:= will be used for updates, not =, because using = makes no sense and no language should have done it in the first place.

:= is just a regular function (:=) : [T] -> (&mut T) -> (T) -> () . It takes in a mutable reference and updates the memory at that location to a new value.